Display device and method of driving the same

Abstract

A display device includes a polymer layer including dichroic dyes and a liquid crystal, which is not mixed or reacted with the polymer layer, dispersed in the polymer layer. The polymer and the liquid crystal have different refractive indices from each other.

What is claimed is: 
     
       1. A display device comprising:
 first and second electrodes configured to face each other and spaced apart from each other; 
 a polymer layer configured to fill a space between the first and second electrodes and include dichroic dyes; and 
 a liquid crystal immiscible with materials in the polymer layer, 
 wherein the polymer layer comprises a reactive monomer or oligomer, and a radical initiator, 
 wherein the reactive monomer or oligomer comprises trimethylolpropane ethoxylate triacrylate (TMPEOTA), 
 wherein the radical initiator includes benzophenone, and 
 wherein the dichroic dye comprises a blue dye comprising a structure of Formula 1: 
 
       
         
           
           
               
               
           
         
       
       R 1  being —NC 2 H 6 , R2 being —OH, and each of R3 and R4 being —NC 4 H 10 . 
     
     
       2. The display device of  claim 1 , wherein, with respect to light incident on the display device, a refractive index of the polymer layer is different from a refractive index of the liquid crystal. 
     
     
       3. The display device of  claim 1 , wherein the reactive monomer or oligomer further comprises at least one selected from the group consisting of triethylopropane triacrylate (TMPTA), tri(propylene glycol) diacrylate (TPGDA), penthaerithritol triacrylate (PETA), methyl methacrylate (MMA), methacrylate (MA), tri(propylene glycol) glycerolate diacrylate (TPGDA), vinylacrylate (VA), ethylene glycol dimethacrylate (EGDA), epoxy acrylate monomer or oligomer, 1,6-hexandiol diacrylate (HAD), styrene (ST), divinyl benzene (DVB), acrylonitrile (AN), vinylidene chloride (VDC), vinylbenzyl chloride (VBC), vinyl stearate (VS), and vinyl propionate (VP). 
     
     
       4. The display device of  claim 1 , wherein the radical initiator further comprises at least one of a photoinitiator, a thermal initiator, and an initiator using a redox reaction. 
     
     
       5. The display device of  claim 4 , wherein the photoinitiator comprises at least one selected from the group consisting of 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1 [4-(methylthio)phenyl]-2-morpholinopropane-1-one, 1-hydroxy-2-methyl-1-phenyl-propane-1-one, an initiator in which 50 wt % of 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropane-1-one and 50 wt % of the benzophenone are mixed, an initiator in which 20 wt % of 1-hydroxy-cyclohexyl-phenyl-ketone and 80 wt % of 1-hydroxy-2-methyl-1-phenyl-propane-1-one are mixed, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1propanone, methylbenzoylformate, alpha,alpha-dimethoxy-alpha-phenylacetophenone, 2-benzyl-2-(dimethylamino)-1[4-(morpholinyl) phenyl]-1-butanone, an initiator in which 30 wt % of -benzyl-2-(dimethylamino)-1-[4-(morpholinyl) phenyl]-1-butanone and 70 wt % of alpha,alpha-dimethoxy-alpha-phenylacetophenone are mixed, diphenyl (2,4,6-trimethylbenzoyl)-phosphine oxide, an initiator in which 50 wt % of diphenyl (2,4,6-trimethylbenzoyl)-phosphine oxide and 50 wt % of 1-hydroxy-2-methyl-1-phenyl-propane-1-one are mixed, phosphine oxide, phenyl bis(2,4,6-trimethyl benzoyl), an initiator in which 5 wt % of phosphine oxide, phenyl bis(2,4,6-trimethyl benzoyl) and 95 wt % of 1-hydroxy-2-methyl-1-phenyl-propane-1-one are mixed, an initiator in which 10 wt % of phosphine oxide, phenyl bis(2,4,6-trimethyl benzoyl) and 90 wt % of 1-hydroxy-2-methyl-1-phenyl-propane-1-one are mixed, an initiator in which 20 wt % of phosphine oxide, phenyl bis(2,4,6-trimethyl benzoyl) and 80 wt % of 1-hydroxy-2-methyl-1-phenyl-propane-1-one are mixed, bis(.eta.5-2,4-cyclopentadien-1-yl) bis[2,6-difluoro-3-(1h-pyrrol-1-yl)phenyl]titanium, a mixed initiator containing the benzophenone, and 1-hydroxy-cyclohexylphenyl-ketone. 
     
     
       6. The display device of  claim 4 , wherein the thermal initiator comprises at least one selected from the group consisting of benzoyl peroxide (BP), acetyl peroxide (AP), diauryl peroxide (DP), di-tert-butyl peroxide (t-BTP), cumyl hydroperoxide (CHP), hydrogen peroxide (HP), potassium peroxide (PP), 2,2′-azobisisobutyronitrile (AIBN), an azo compound initiator, and silver alkyls. 
     
     
       7. The display device of  claim 4 , wherein the initiator using a redox reaction comprises potassium persulfate (K 2 S 2 O 8 ) and a redox initiator. 
     
     
       8. The display device of  claim 1 , wherein the dichroic dye further comprises a red dye and a green dye. 
     
     
       9. The display device of  claim 8 , wherein the red dye comprises a structure of Formula 3: 
       
         
           
           
               
               
           
         
         wherein R 7  comprises at least one selected from the group consisting of chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), vanadium (V), niobium (Nb), and tantalum (Ta), R 8 , R 9 , R 10 , and R 11  are a same or different, and R 8 , R 9 , R 10 , and R 11  comprise at least one selected from the group consisting of —NO 2 , —NH 3 , —NHCH 3 , —NC 4 H 10 , —NC 2 H 6 , —N(alkyl chain having 3 or more carbon atoms), and one or more aromatic groups. 
       
     
     
       10. The display device of  claim 8 , wherein the red dye comprises a structure of Formula 4: 
       
         
           
           
               
               
           
         
         wherein R 12  comprises at least one selected from the group consisting of —SO 3 Na and —SO 3 H, R 13  comprises at least one selected from the group consisting of —COOH and —COONa, R 14  and R 15  are a same or different, R 14  and R 15  comprise at least one selected from the group consisting of —H, —CH 3 , —C 2 H 5 , a linear alkyl group having 3 or more carbon atoms, a branched alkyl group having 3 or more carbon atoms, a linear alkene having 3 or more carbon atoms, a branched alkene having 3 or more carbon atoms, —NC 4 H 10 , —NC 2 H 6 , —NHCH 3 , —NH 2 , —N(alkyl chain having 3 or more carbon atoms), and one or more aromatic groups, and R 16  comprises at least one selected from the group consisting of —H, —OH, —SO 3 H, and —COOH. 
       
     
     
       11. The display device of  claim 8 , wherein the green dye comprises a structure of Formula 5: 
       
         
           
           
               
               
           
         
         wherein R 17  and R 18  are a same or different, and R 17  and R 18  comprise at least one selected from the group consisting of structures below: 
       
       
         
           
           
               
               
           
         
       
     
     
       12. A method of driving the display device of  claim 1 , the method comprising:
 incidenting light on the display device; 
 generating a color by refraction of the incident light caused by a difference between a refractive index of the polymer layer and a refractive index of the liquid crystal and scattering the incident light by the dichroic dyes in the polymer layer when there is no potential difference between the polymer layer and the liquid crystal; and 
 displaying black by transmitting the incident light by allowing the liquid crystal to have a same refractive index as the refractive index of the polymer layer by aligning liquid crystal molecules of the liquid crystal in one direction when a potential difference is generated between the polymer layer and the liquid crystal. 
 
     
     
       13. The method of  claim 12 , further comprising:
 generating light from light-emitting devices in a dark environment, the display device including the light-emitting devices.